Resin and method of preparing the same



Patented Feb. 7, 1928.

UNITED STATES PATENT OFFICE.

mnmb BEU'INEB, OI LOUISVILLE, KENTUCKY, ASSIGNOB TO AUG. NOWAGK LK'IIENGESELLSOHAIT, OI BAUTZEN, GERMANY, A CORPORATION OF GERMANY.

RESIN AND METHOD OF PREPARING THE SAME.

R Drawing.

The new methods relate to an im rovement in the making of henol formal ehyde condensation products bakelite, etc.). Such roducts' have been (prepared heretofore rom formaldehyde an cresol (or henol).

The cresol or the like is obtained rom tar oil by means of an alkaline extraction in the well known manner.

According to the present 1nvent1on ord1- nary tar oil can be used, as such, without separating hydrocarbons and acid constituents. This separation is performed by means of and simultaneously with the condensation with formaldehyde, leading to the production of resin.

Before describin the process roper, some experiments descri ed by Gluu and Breuer in F. Fischers Gesammelten Abhandlungen zur Kenntnis der Kohle 4,230, (1919-) 20 should be mentioned. These authors were the first ones to try the use of F. Fischers low temperature tar (Urteer) for the making of condensation products (in laboratory experiments). They found that they could use crude low tem erature tar which. by distilling, had been iberated from its highest boiling constituents. They observed that the hydrocarbons did not interfere with the reaction, but could be removed from the resinous products after the reaction had been completed. Theyl (G1. and B.) obtained, however, only un ardenable pitchlike resins in this way which could not be hardened by heating, and would be, therefore, of little practical value.

Another factor which would prevent a commercial adaptation of these experiments would be the impossibility of reproducing such cfiects with the ordinary high tem erature tar which is generally on the mar et. Experiments were erformed in which ordinary tar, liberate from its most viscous compounds was boiled with formaldehyde in the manner described by Gluud and Breuer; no separation of the layers as described by them was observed. With ordina high temperature tar the hydrocarbons o interfere with the reaction; they stay in the final product and deteriorate its pro erties, making it unhardenable and pitchli (At the same time control experiments were performed verifying Gluud and Breuera statement concerning low temperature tar.)

The present invention, therefore, deals Application filed November 15, 1524. Serial No. 750,034.

with the condensation of high temperature tar and fractions thereof and describes the production of resins by a direct process which 1. Spontaneously separates the hydrocar bons.

2. Yields hardenable resins.

Several methods have been found which attain this end. The first one consists in adding to the coal tar or coal tar oil distilled from it, each containing tar acids, small amounts of hydrocarbons. preferably aliphatic hydrocarbons (mineral oil). or other solvents like chlorinated hydrocarbons, which do not dissolve the resin, have a specific gravity, smaller than water, and are miscible with the hydrocarbons of the tar oil. Such additions produce a separation of the hydrocarbons as is illustrated by the following experiment.

200 parts of 25% tar acid oil (from the Barrett Co. of New 'ork) were mixed with 40 parts of commcrcial kerosene, 80 parts of 40% formaldehyde and 25 parts of a normal sodium hydroxide solution: the mixture was heated to boiling on a reflux condenser for half an hour. After that, on cooling, the mixture settled into three distinct layers, viz, 190 parts of an oily layer on the top. consisting essentially of hydrocarbons, 85 parts of an aqueous layerin the center, and 75 parts at the bottom of the vessel.

These three layers were separated and analyzed. The top layer proved to consist chiefly of volatile constituents; up to 250 Celsius 170 cc. distilled. after carrying on the distillation up to 300 a residue of about 7 parts of pitch remained. The distillate was. then. shaken with concentrated alkali in order to determine its content of acid constituents. this being 7%. This shows that by the condensation, the tar acids have been taken out by the tar oil (diminishing from 25 7%).

The resin, settling at the bottom of the reaction vessel. was heated and thus transformed into solid A which diminished its weight to parts. It appeared as a thick brown mass. containing only little hydrocarbons. By suflicient heating it was transformed into the insoluble and infusible (3" which exhibited considerable hardness and toughness.

Trying to repeat this ex riment without kerosene, no separation 0 layers was obluu llm

above. The Barrett tar acid oil, used in the experiments, described above, is completely liberated from the most viscous compounds, more so that the products, used by Gluud and Breuer, as is proven by its boiling range which was found to be the following:

% boiling up to 200.

% boiling up to 215.

80% boiling up to 230.

The rest up to 300.

There was practically no pitch.

It was found that, if the tar oil containing tar acids is still further refined, it can be condensed with formaldehyde directly and the separation of the hydrocarbons may be obtained just as well without adding a solvent.

The following experiment may serve as an example:

By repeated distillation a low boiling tar oil containing tar acids was prepared from the Barrett oil, characterized by the following boiling range:

% boiling up to 190.

87% boiling up to 200.

96% boiling u to 210.

200 arts of t is oil were boiled with 100 parts ormaldehyde and 30 parts of normal ydroxide solution for 45 minutes. Although no solvent had been added. the mixture conpletely settled into three layers as describe above.

The oily top layer was analyzed by distillation; it yielded a volatile oil containing 7% of acid constituent.

The resin, which settled at the bottom of the reaction vessel had excellent hardening properties. It resembled a bakelite resin, yet its mechanical properties appeared to e superior to bakelite owing to its greater elasticity and higher dielectric constants. This was found out by dissolving the resin in alcohol and producing coatings with it;

also another part of it was used for impreg.

nating moulding mixtures.

This experiment shows that by completely refining t e tar oil, the separation of the resinous constituents and the noncondensable hydrocarbons can be attained. This is easily hardenable resins. From a number of such ex eriinents it appeared that the best metho would be in general, to use tar oils, havin approximately the same boiling range as t. e cresol or phenol (the condensation of which is desired) contained therein.

The best results, as regards quality of the resins and sepnrationof the layer are obtained by combining the two above methods (addin of solvents and'cutting out of the higher boiling constituents).

In condensing tar oil, as described, it is not possible in all cases to bring all the cresol, contained in the oil, into reaction. The oil, separated after the condensation on the top, may contain 540% acid constituents, especially so if little formaldehyde is used. The following method has been de vised for extracting all cresols from the tar ail;1 without using an excess of formalde- A batch of tar oil is at first treated with formaldehyde and alkali in a reflux condenser as described, the amount of formaldehyde used being insufiicient to combine with all of the phenols contained in the vbatch of oil. The resin product of the foregoing treatment consequently contains appreciable amounts of phenols and -the oil layer also retains ap reciable amounts of phenols. The said oil ayer u on separation from the resin is again treate with formaldehyde and alkali, as before, but as the more readily extractable phenol content of the'oil was removed in the first step, the resinous product of the second treatment contains free formaldehyde. Mixture of the resinous product of the first operation and the resinous product of the second operation affords an opportunity of a condensation reaction between the free phenols of one and the free formaldehyde of the other, thereby yielding a product which is relatively free from either phenols or formaldehyde. Of course, in this case, if the excess of formaldehyde in the resinous roduct of the second operation is greater t nm the excess of free phenols in the resinous products of the first operation (as is usually the case for the reasons heretofore explained) a corresponding amount of pure cresol or phenol will have to be added to the mixture of the two resinous produdts before the condensation step.

The oil layer from the second treatment after separation is preferably extracted with alkali in the usual manner to remove as far as possible the recoverable phenols in the original tar oil. The resultant solution containing alkali and phenol. may obviously be dealt with in any suitable manner for the recovery of the phenol or may be used as a part of the condensation agent in any of the preceding condensation treatments as heretofore described.

Intermediate between the second treatment as above described and the final alkali extraction step, repeated successive treatments with new lots of formaldehyde may be introduced. Excess formaldehyde in the aqueous layers formed during any of the treatments may obviously be used in connection with new lots of tar oil.

Extraction of the phenols by means of formaldehyde condensation'and by means of alkaline extraction may also be combined differently, e. g. by making one formaldehyde condensatlon and. after that, one alkaline extraction.

The hydrocarbons of the tar oil so arated on the to of the aqueous phase a er the condensation were shaken with dilute acid in order to remove basic constituents and redistilled. It was found that by this operation a colorless liquid with an agreeable smell was obtained, different from the hydrocarbons, se arated from the tar oil by the old metho of alkaline extraction. The hydrocarbons, separated after condensation, contain small amounts of esterlike substances which cause their agreeable smell. Owing to this property they are better suitable as solvents than ordinary hydrocarbons. This method of preparing hydrocarbons is another application of the new method of direct condensation.

The processes, described, can be produced in the same way by using other aldehydes instead of formaldehyde. Although the character of the resin is modified according to the aldehyde used. the separation of the layers takes place in the same way, the properties of the hydrocarbons (top oil) not being essentially affected.

I claim:

1. The method of forming phenol con densation products directly from coal tar oils which comprises mixing a coal tar oil containing tar acids with an aliphatic solvent, a solution capable of extracting the said tar acids fromthe tar oil and to catalyze the condensation reaction. and a solution containing an aldehyde-bearing material, heating said mixture until a reaction has occurred between the aldehyde and the phenols in said mixture, permitting the said mixture to separate into immiscible layers, the top layer being of an oily nature. the middle layer of an aqueous nature; and the bottom layer of a resinous nature. and withdrawing the said layers separately.

2. The method of forming phenol condensation products directly from coal tar oils which comprises adding a coal tar oil containing tar acids. kerosene, a caustic alkali solution, and :1. formaldehyde solution together to form a mixture, heating the said mixture until a reaction between formaldehyde and the phenols in said tar oils. causing a separation of said mixture into three immiscible layers, the top layer being of an oily nature. the middle layer of an aqueous nature, and the bottom layer of a resinous nature, and separating the said layers from each other.

3. The method of forming phenol condensation products directly from coal tar oils which comprises adding a coal tar oil boiling below 300 0. containing tar acids, kerosene, a normal solution of caustic soda, and formaldehyde together to form a mixture, boiliug said mixture until a condensation between formaldehyde and the phenols in said Mr oils has occurred, continuing said boiling until the said condensation reaction is substantially complete, allowing the said mixture to separate into three immlscible layers, the top layer being of an oily nature, the middle of an aqueous nature, and the bottom of a resinous nature, and separating the said layers from each other.

4. The method of forming phenolcondensation products directly from coal tar oils which comprises adding a coal tar oil boiling below 220 C. containing tar acids, a solution having the'power to extract tar acids from the tar oil and to catalyze the condensation reactionof the said tar acids with an aldehyde, an aldehyde bearing substance, together, boiling said mixture unt l the condensation reaction between the said tar acids and the said aldehyde bearingmatenal has occurred, then allowing said mlxture to separate into three immiscible layers,the top la er having oily compounds therein, the middle layer having substances in aqueous solution. and the bottom layer having a hardenable resinous material, and separating said layers from each other.

5. The method as specified in claim 4 in which tlie condensation reaction occurs in the presence of an alifphatic solvent.

6. The method of orming phenol condensation products directly from tar oils which comprises treating tar oils contaimng tar acids with an alkaline solution and an aldehyde insufficient in amount to combine with all the tar acids, separating the mixture into three component parts. one part being of an oily nature containing tar acids, a second part being of an aqueous nature, and a third part being of a resinous nature, treating said oily part with furtheramounts of aldehyde and alkaline solutions, and repeating the aforesaid operations until substantially all of the tar acids have been removed from the tar oils.

7. The method of preparing a solvent from the direct condensation of tar oils which comprises treating tar oils containing tar acids with an alkaline solution and an aldehyde to cause a condensation reaction between the said tar acids and aldehyde, separating the oil having a density less than water from said mixture. and purifying said oil to produce a solvent.

8. The method as specified in claim 7 in which the, condensation reaction takes place in the presence of an aliphatic kerosene solvent. A

9. The method of forming phenol condensation products directly from tar oils which comprises treating tar oils containing tar acids with an alkaline solution and an aldehyde insufficient in amount to combine a. third part being of a resinous nature, treatin said oil art with further amounts of alde yde and a kaline solutions separating the resins formed in said preceding step, mixing the last mentioned resins with the resinous product of the treatment first described, andcausing a condensation reaction to occur between the free phenols contained in the resinousproduct of the first treatment and the free formaldehyde contained in the resins of said last mentioned treatment.

B. BEUTNER.

8. The method as specified in claim 7 in which the condensation reaction takes place in the presence of an aliphatic kerosene solvent.

9. The method of forming phenol condensation products directly from tar oils which comprises treating tar oils containing tar acids with an alkaline solution and an aldehyde insufiicient in amount to combine with all the tar acids, separating the mixture into three component parts. one part being of an oily nature containing tar acids, a second part being of an aqueous nature, and

a third part being of a resinous nature, treatinl said oily part with further amounts of alde yde and alkaline solutions, separatmg the resins formed in said preceding step, mixing the last mentioned resins with the resinous product of the treatment first described, and causing a condensation reaction to occur between the free phenols contained in the resinous product of the first treatment and the free formaldehyde contained in the resins of said last mentioned treatment.

B. BEUTNER.

DISCLAIMER H y p a 1,658,281.Reinkard Bumer, Louisville, Ky. Rssnv AND METHOD or PREPARING THE SAME.- Patent dated February 7, 1928.

Disclaimer filed December 13,

1929,1 37 the assignee Aug. Nowack Akt'iengesellschafi. I Hereby'disclahn from the'scope of claim 4 of Patent No.v1, 658,281 any method of forming phenol condensation products such as areset forth in said fourth claim of said patent in which the coal tar oil boiling below 220 is a coal tar oil derived from f so-called low-temperature tar or a tar other than suchhs isderived from so-called high-tam eratnre coal tar and has been distilled untilsubstantially the whole of the 4 distillate ils below 220 C.

The term low temperature here ein l'oyed is intended to refer to any tar 3 obtainedby carbonization' of coal in w "ch,-when distilled by the standard method D20 v18'0f the American Societ for Testing Materials, for the distillation of bituminous materials suitable for roa, treatment,the total fraction of distillate coming over betweenlthelva or temperatures of 170 and 300 (3., shall com ly with either of the following spec' cationszKa) the quantity of materials extracta 1e from the distillate by a 10% sodium-hydroxide solution shall exceed 15% by volume, (b) the hydrocarbon portion of the said distillate remaining after the complete removal therefrom of tar acids and tar bases shall give, after exhaustive treatment with 98% sulphuric acid at room temperature, a sulphonation residue exceeding 10% of the tar "acid free and tar base free hydrocarbons.

[Qficial Gazette January 7, 1980.] I,

DISOLAlMER 1,658,281.Reinlmrd Beutner, Louisville, Ky. RESIN AND METHOD or PREPARING THE SAME.- Patent dated February 7, 1928. Disclaimer filed December 13, 1929, by the assignee Aug. Nowack Alctt'engesellschafi.

Herebydisclaim from the scope of claim 4 of Patent No..1,658,281 any method of forming phenol condensation products such as are set forth in said fourth claim of said patent in which the coal tar oil boiling below 220 C is a coal tar oil derived from so-called low-temperature tar or a tar other than suohas is derived from so-called high-tom rature coal tar and has been distilled until substantially the whole of the distillate iitlils below 220 C.

The term low temperature tar as here em loyed is intended to refer to any tar obtainedlby the carbonization of coal in -w "ch,'-when distilled by the standard method D20 r18of the American Societ for Testing Materials, for the distillation of bituminous materials suitable for roa treatment,'the total fraction of distillate coming over between the .va or temperatures of 170 and 300 C., shall com ly with either of the following specifications: '(a) the quantity of materialsextracta le from the distillate by a 10% sodium-hydroxide solution shall exceed 15% by volume, (11) thelhydrocarbon portion of the said distillate-remaining after the complete removal therefrom of tar acids and tar bases shall give, after exhaustive treatment with 98% sulphuric acid atroom temperature, a sulphonation residue exceeding 10% of the tar acid free and tar base free hydrocarbons.

[Qflic'ial Gazette January 7, 1930.} 

